Sewing Machine

ABSTRACT

Illuminating device includes a plurality of LEDs positioned at intervals so as to form a linear LED array generally corresponding to an array line along which needle bars are provided, and a lens for gathering emitted light from the LEDs to thereby generate a linear light beam corresponding to the array line. The illuminating device provided in each machine head is controlled, independently of the illuminating devices of the other machine heads, in response to an operating state of the machine head. Thus, it is possible to not only generate, at low cost, a linear light beam suited to illumination of areas around the points of a plurality of needles arranged in a linear array, but also appropriately control the needle point illumination for the plurality of machine heads.

TECHNICAL FIELD

The present invention relates to sewing machines provided with anilluminating device for illuminating areas around needle pointsimmediately beneath a machine head.

BACKGROUND ART

Heretofore, there have been known sewing machines provided with anilluminating device for illuminating areas around the points of needles(i.e., needle points) and surface of a sewing fabric so that needlethreading operation and inspection of a pattern sewn on a sewing fabriccan be performed with ease. Japanese Patent Application Laid-openPublication No. HEI-11-253685 discloses a sewing machine which includesa plurality of needle bars provided on a machine head, and anilluminating device for illuminating an area around the point of aneedle fixed to the lower end of each needle bar and surface of a sewingfabric. The illuminating device, which is capable of emitting a linearlight beam generally along an array line along which the needle bars aredisposed, comprises, for example, a cold cathode fluorescent lamp orplanar light-emitting member formed in a linear shape, or a plurality ofhigh-intensity dot-shaped light-emitting members (e.g., LEDs) disposedin a linear array. With such an illuminating device capable of emittinga linear light beam, it is possible to sufficiently illuminate the areaaround the point of each needle and surface of the sewing fabric.

Also known are sewing machines constructed to control the illuminatingdevice in response to an operating state of the machine. Japanese PatentNo. 2900549 discloses a sewing machine which, when an anomaly orabnormal condition has been detected by an abnormal condition detectionmeans that detects false operation, accident (e.g., thread breakage) orthe like, changes the color of the light emitted from the illuminatingdevice to inform of the abnormal condition. Further, Japanese PatentApplication Laid-open Publication No. HEI-6-91085 discloses another typeof automatic sewing machine which detects a start and end of automaticsewing so as to deilluminate the illuminating device upon detection ofthe start of automatic sewing and illuminate the illuminating deviceupon detection of the end of the automatic sewing; in this way, thissewing machine can spare a human operator the trouble of operating theswitch of the illuminating device in order to save power consumption.

In recent years, there has been a tendency to use, as the illuminatingdevice for illuminating an area around a needle point and surface of asewing fabric, an LED lamp that can be significantly reduced in size andincreased in operating life and that can effectively prevent undesiredheat production. However, because illumination (light emission) by theLED lamp as a unitary light source is limited to a small spot-shapedrange, a multiplicity of LED lamps have to be disposed in a linear arraywith almost no gap in order to illuminate areas around the points of theindividual needles of a multi-needle sewing machine, which wouldinevitably require an increased cost. With a multi-head, multi-needletype sewing machine including a plurality of multi-needle type machineheads, the necessary cost would increase in proportion to the number ofthe machine heads.

On the other hand, in the conventionally-known sewing machine of thetype constructed to control the illuminating device in response to anoperating state of the sewing machine as disclosed in Japanese PatentNo. 2900549 or Japanese Patent Application Laid-open Publication No.HEI-6-91085, only one illuminating device is controlled in response toan operating state of the machine. Thus, in multi-head sewing machinesprovided with a plurality of machine heads, it has of course beenimpossible to control the illuminating device of each of the machineheads independently of the illuminating devices of the other machineheads, and it has also been impossible to control the individualilluminating devices in response to operating states of thecorresponding machine heads.

DISCLOSURE OF THE INVENTION

In view of the foregoing, it is an object of the present invention toprovide a sewing machine provided with an illuminating device that cangenerate, at low cost, a linear light beam suited to illumination ofareas around the points of individual needles disposed in a linear array(i.e., needle point illumination). It is another object of the presentinvention to provide a sewing machine which can appropriately controlneedle point illumination for a plurality of machine heads.

The present invention provides an improved sewing machine provided witha multi-needle machine head having a plurality of needle bars disposedin a straight or curved linear array, which includes an illuminatingdevice for illuminating an area around a point (needle point) of asewing needle fixed to the lower end of each of the needle bars. Theilluminating device comprises: a plurality of unitary light sourcesdisposed at intervals, or with some gaps therebetween, so as to form alinear array of the light sources generally corresponding to a needlebar array line along which the needle bars are disposed; and a lensprovided for covering the plurality of unitary light sources to gatherlight emitted from the individual unitary light sources, to therebygenerate a linear light beam corresponding to the needle bar array line.

According to another aspect of the present invention, there is provideda sewing machine provided with a plurality of machine heads, whichcomprises: an illuminating device provided for each of the machine headsfor illuminating an area around a point of a sewing needle of themachine head; and a control section for controlling the illuminatingdevice of each of the machine heads in response to an operating state ofthe machine head.

By the provision of the illuminating device constructed in theaforementioned manner, the emitted light from the plurality of theunitary light sources disposed at intervals can be gathered, via thelens, to be converted into a linear light beam so that the areas aroundthe points of the individual sewing needles can be illuminated evenlyover a wide range with a small number of the unitary light sources,which can thereby minimize the manufacturing cost of the illuminatingdevice. Further, in cases where the present invention is applied to amulti-head sewing machine, the necessary manufacturing cost can bereduced synergistically. Furthermore, where chip LEDs (Light EmittingDiodes) are used as the unitary light sources, the unitary light sourcesnot only can be reduced in size and increased in operating life but alsocan effectively prevent undesired heat production.

By controlling each of the machine heads in response to an operatingstate of the machine head, it is possible to perform optimalneedle-point illumination control on each of the machine heads,independently of the other machine heads, in the multi-head sewingmachine, in response to the operating state of the machine head. Forexample, when only one or some of the plurality of machine heads are tobe caused to operate with the other machine heads in a non-operatingstate, it is possible to perform control for illuminating theilluminating devices of only the machine heads that are to be caused tooperate. Alternatively, when the sewing machine has stopped operating orshut down due to occurrence of a thread breakage, it is possible toperform control for illuminating only the illuminating device of themachine head where the thread breakage has occurred. In this way, ahuman operator is allowed to advantageously identify, at a glance, eachoperating or non-operating machine heads, and perform sewing operationand illumination control with no waste.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a view showing an outer appearance of a multi-head,multi-needle embroidery sewing machine in accordance with an embodimentof the present invention;

FIG. 2 is a front view of the machine head in the embodiment;

FIG. 3 is a side view, partly in section, of the machine head in theembodiment;

FIG. 4 is a perspective view showing an example of an illuminatingdevice in the embodiment;

FIG. 5(A) is a sectional side view of the illuminating device in theembodiment, and FIG. 5(B) is a sectional side view showing amodification of the illuminating device; and

FIG. 6 is a block diagram showing a control system of a control deviceand illuminating devices in the embodiment of the embroidery sewingmachine.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present invention will hereinafter be described withreference to the accompanying drawings.

FIG. 1 is a view showing an outer appearance of a multi-head,multi-needle embroidery sewing machine in accordance with an embodimentof the present invention, where reference numeral 1 indicates a machineframe, and 2 a table. A plurality of (four in the illustrated example)machine heads 3 are disposed at equal intervals along a left-righthorizontal direction of the sewing machine, and a needle plate 4 isdisposed immediately beneath each of the machine heads 3 and atgenerally the same height position as the table 2. On the upper surfaceof the table 2, there is placed an embroidery frame 5 that is driven infront-rear and left-right horizontal directions via an X-axis drivemechanism and Y-axis drive mechanism (not shown).

FIG. 2 is a front view of the machine head 3, and FIG. 3 is a side view(partly in section) of the machine head 3. As clear from these figures,each of the machine heads 3 comprises an arm 6 fixed to the machineframe 1, and a needle bar case 7 slidably supported on the front surfaceof the arm 6. A plurality of (nine in the illustrated example) needlebars 8 are vertically-movably provided in the needle bar case 7, and asewing needle 9 is fixed to the lower end of each of the needle bars 8.The needle bar case 7 is caused to slide by a not-shown changemechanism, so that a desired one of the needle bars 8 can be located ata selected position and the thus-selected needle bar 8 is drivenvertically via a not-shown needle bar drive mechanism. Sewing isperformed in the conventionally-known manner through cooperation betweenthe vertically-driven needle bar 8 (sewing needle 9) and a not-shownrotary hook provided beneath the needle plate 4, and embroidery sewingis performed, on the basis of embroidery data, by the embroidery frame 5being driven in the front-rear and left-right directions as well as bythe cooperation between the vertically-driven needle bar 8 (sewingneedle 9) and the rotary hook.

Illuminating device 10 is provided on a front lower surface portion ofthe needle bar case 7. As shown in a perspective view of FIG. 4 andsectional side view of FIG. 5(A), the illuminating device 10 generallyhas a semi-cylindrical shape. The illuminating device 10 includes a baseplate 12 having a plurality of (four in the illustrated example) chipLEDs 11 provided at equal intervals thereon, a base member 13 fixing thebase plate 12, and a lens 14 provided to cover the base plate 12. Thenumber of the chip LEDs 11 on the base plate 12 is smaller than thenumber of the needle bars 8 arranged in the needle bar case 7, and thechip LEDs 11 are disposed on the base plate 12 at intervals to form alinear array (straight linear array in the illustrated example)substantially corresponding to a needle bar array line along which theneedle bars 8 are disposed on the base plate 12. The lens 14 is in theform of a substantially-semicylindrical lens that can gather incominglight through its flat surface portion and emit a linear light beamthrough its cylindrical surface portion, and the lens 14 is formed of,for example, an acrylic material. The semicylindrical lens 14 has atotal length corresponding to a total length of the needle bar arrayline along which the needle bars 8 are arrayed in the needle bar case 7,and the lens 14 has a shape corresponding to the array line (straightline in the illustrated example) along which the needle bars 8 aredisposed. This lens 14 gathers respective emitted light from theplurality of chip LEDs 11 to thereby emit a linear light beam that canevenly illuminate areas around the points of the individual sewingneedles 9. Thus, the light emission from the small number of (four inthis case) chip LEDs 11 of the illuminating device 10 can evenlyilluminate the areas around the points of the nine sewing needles 9greater in number than the four chip LEDs 11 of the illuminating device10. Whereas, in the illustrated example, the needle bars 8 are disposedin the needle bar case 7 in a straight linear array, the needle bars 8are sometimes disposed in a curved array, such as a circular array, inwhich case the longitudinal shape of the illuminating device 10 isformed into a curved shape corresponding to the shape of the array ofthe needle bars 8; thus, an array line along which the plurality of chipLEDs 11 are arranged and the longitudinal shape of the semicylindricallens 14 are also set to a curved line and curved shape, respectively.

As shown in FIG. 6, an illuminating drive control signal is suppliedfrom a control device 20 of the embroidery sewing machine separately tothe illuminating device 10 of each of the machine heads 3 (the fourmachine heads 3 are indicated in the figure by #1 to #4 for clearerdistinction) via a driver 21. Illumination and deillumination (i.e.,turning-on and turning-off) of each of the illuminating devices 10 iscontrolled by the control device 20 in accordance with an operatingstate of the sewing machine and an operating state of the correspondingmachine head 3. For example, the control is performed in such a mannerthat the illuminating device 10 is deilluminated when the sewing machineis in the operating state because there is no need to illuminate theareas around the needle points, but the illuminating device 10 isilluminated when the sewing machine has stopped operating. In some case,the multi-head type sewing machine is operated with only one or some ofthe machine heads 3 in the operating state with the remaining machinehead(s) 3 in the non-operating state. If, in such a case, the sewingmachine has stopped operating, the control is performed, independentlyfor each of the machine heads, in such a manner only the illuminatingdevice 3 of each machine head 3 set in the operating state isilluminated with the illuminating device 10 of each machine head 3 setin the non-operating state kept deilluminated. In this way, the humanoperator not only can advantageously identify, at a glance, each machinehead 3 to be in the operating state, but also can avoid a waste of, forexample, illuminating the illuminating device 10 of any of thenon-operating machine heads 3 which does not need to be illuminated.Further, by performing the illumination control independently for eachof the machine heads as noted above, the control can be performed sothat, when the sewing machine has stopped operating or shut down due toa thread breakage, only the illuminating device 10 of the machine head 3where the thread breakage has occurred is illuminated. Thus, when thesewing machine has stopped operating or shut down due to a threadbreakage, the human operator not only can easily identify in which ofthe machine heads the thread breakage has occurred, but also can avoid awaste of illuminating the illuminating device 10 of any of the othermachine heads 3 where the thread has not been broken and hence there isno need to illuminate the illuminating device 10. In order to performsuch head-by-head illumination control, it is only necessary to prepareand install a necessary computer program and cause a CPU of the controldevice 20 of the sewing machine to execute the program. In such a case,information for setting operation (i.e., activation/deactivation) ofeach of the machine heads 3, thread breakage detection signal of each ofthe machine heads 3, information indicative of a current operating stateof the sewing machine, etc. are input to the control device 20 of thesewing machine, and the aforementioned illumination control is performedindependently for each of the machine heads 3 by the control device 20referring to these input signal and information. However, the presentinvention is not limited to such program-based illumination control, andnecessary hardware circuitry for performing the illumination control maybe fabricated and incorporated into the control device 20 of theembroidery sewing machine.

FIG. 5(B) shows a modification of the illuminating device. Although thismodified illuminating device 15 functions similarly to theaforementioned illuminating device 10, the flat surface portion of thecylindrical lens has a slightly different shape from that of theaforementioned illuminating device 10. Namely, whereas the flat surfaceportion of the cylindrical lens 14 of the illuminating device 10 shownin FIG. 5(A) has a groove formed therein for positioning the chip LEDs11, the entire flat surface portion of the cylindrical lens 16 of theilluminating device 15 shown in FIG. 5(B) is formed flat, and a spacer17 is interposed between the flat surface portion and the base member 13so that a slight space is formed, by the provision of the spacer 17, forappropriately positioning the chip LEDs 11. While the cylindrical lens14 shown in FIG. 5(A) requires formation of the groove in the flatsurface portion, the cylindrical lens 16 shown in FIG. 5(B) does notrequire formation of such a groove and thus can be simplified inconstruction.

Whereas, in the above-described embodiment of the invention, theilluminating device 10 (or 15) corresponding to one of the machine heads3 is constructed as a one-piece unit, the present invention is not solimited, and a plurality of units of the illuminating device 10 (or 15)may be provided, depending on the number of the needle bars per machinehead 3, by combining the units into a horizontal array along the arrayline of the needle bars, to thereby provide an illuminating means forthe machine head 3. For example, two chip LEDs 11 may be used to providean illuminating device unit having about half of the length of theilluminating device 10 shown in FIG. 4, and only one such short-lengthilluminating device unit may be provided per machine head 3 where themachine head 3 has just four or five needle bars; however, two suchshort illuminating device units may be provided horizontally per machinehead 3 where the machine head 3 has nine needle bars. In anotheralternative, the illuminating device unit having about a quarter of thelength of the illuminating device 10 shown in FIG. 4 may be constructedusing only one chip LED 11. In such case, one chip LED 11 is positionedcentrally in the longitudinal or length direction of the lens 14 (or16), and one or more short illuminating device units, each comprisingthe one chip LED 11 and corresponding cylindrical lens 14 (or 16), maybe provided horizontally on the base plate 12, depending on the numberof the needle bars in the machine head 3. Needless to say, illuminatingdevice units of various different lengths may be provided in ahorizontal array on the base plate 12.

By the control device 20 variously setting illuminating styles(illuminating time length, blinking style, illuminating color switchingstyle, etc.), the sewing machine of the present invention can alsoperform various informing functions. For example, the sewing machine ofthe present invention can warn the human operator that a thread breakagehas occurred, by first blinking the illuminating device 10 of themachine head 3, where a thread breakage has occurred, for severalseconds and then illuminating the illuminating device 10. In anotheralternative, when the sewing machine has shut down, for example, due tosome error, all of the illuminating devices 10 may be blinked to informthe human operator of the error. In this case, the illuminating devices10 are brought back to the normal state once the human operator clearsthe error on an operation panel or the like. In an alternative, theremay be provided chip LEDs of a plurality of colors, so as to allowingthe chip LEDs to perform various informing functions by switchingbetween emitted light colors of the LEDs. Note that each of the unitarylight sources may be any other suitable light source than the chip LEDs.Further, the present invention may be applied to any other types ofsewing machines than embroidery sewing machines.

In the preferred embodiment, as having been described above, the emittedlight from the chip LEDs 11 disposed at intervals or with some gapstherebetween is gathered via the lens 14 to be converted into a linearlight beam so that areas around the points of the plurality of sewingneedles 9 disposed in a linear array are illuminated by the linear lightbeam. As a result, the areas around the points of the plurality ofsewing needles 9 can be illuminated appropriately by a small number ofthe chip LEDs 11, which can thereby minimize the necessary manufacturingcost of the illuminating devices, and the necessary manufacturing costof the sewing machine of the multi-head, multi-needle type too can bereduced synergistically. Further, by performingillumination/deillumination control on the illuminating devices 10 ofthe individual machine heads 3 in accordance with the respectiveoperating states of the machine heads 3, it is possible to illuminateonly the illuminating device 10 of each operating machine head 3 or onlythe illuminating device 10 of a particular machine head 3 where a threadbreakage has occurred, with the result that the human operator isallowed to not only readily identify each operating or particularmachine head 3 but also prevent wasteful illumination of theilluminating device 10 of any of the machine heads 3 where noillumination is unnecessary.

1. A sewing machine provided with a multi-needle machine head having aplurality of needle bars disposed in a straight or curved linear array,said sewing machine including an illuminating device for illuminating anarea around a point of a sewing needle fixed to a lower end of each ofthe needle bars, said illuminating device comprising: a plurality ofunitary light sources disposed at intervals so as to form a linear arrayof said light sources generally corresponding to a needle bar array linealong which the needle bars are disposed; and a lens provided forcovering said plurality of unitary light sources to gather light emittedfrom individual ones of said unitary light sources, to thereby generatea linear light beam corresponding to the needle bar array line.
 2. Asewing machine as claimed in claim 1 wherein said lens of saidilluminating device is a single elongated cylindrical lens of apredetermined length, and said plurality of unitary light sources aredisposed at intervals along a longitudinal direction of the cylindricallens.
 3. A sewing machine as claimed in claim 1 wherein said lens ofsaid illuminating device comprises a single elongated cylindrical lensof a predetermined length, and a plurality of illuminating device unitsdisposed in an array along the needle bar array line, each of saidilluminating device units including at least one said unitary lightsource provided in correspondence with said illuminating device.
 4. Asewing machine as claimed in any one of claims 1 wherein each of saidunitary light sources is a chip LED.
 5. A sewing machine as claimed inclaim 1 wherein a number of said unitary light sources is smaller than anumber of said needle bars in said machine head.
 6. A sewing machine asclaimed in claim 1 which is provided with a plurality of the machineheads each including said illuminating device.
 7. A sewing machine asclaimed in claim 6 which further comprises control means for controllingsaid illuminating device of each of the machine heads in response to anoperating state of the machine head.
 8. A sewing machine provided with aplurality of machine heads, said sewing machine comprising: anilluminating device provided for each of the machine heads forilluminating an area around a point of a sewing needle of the machinehead; and control means for controlling said illuminating device of eachof said machine heads in response to an operating state of the machinehead.
 9. A sewing machine as claimed in claim 8 wherein, when only oneor some of said plurality of machine heads are to be caused to operatewith other of said machine heads in a non-operating state, said controlmeans performs control for illuminating the illuminating devices of onlythe machine heads that are to be caused to operate.
 10. A sewing machineas claimed in claim 8 wherein, when said sewing machine has stoppedoperating due to occurrence of a thread breakage, said control meansperforms control for illuminating only said illuminating device of themachine head where the thread breakage has occurred.
 11. A sewingmachine as claimed in claim 8 wherein said control means performscontrol for illuminating said illuminating devices in any of differentilluminating styles corresponding to a plurality of kinds of informingfunctions.